Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 5, NWS Quad Cities, IA

May 2, 2018Cedar County, Johnson County, Muscatine County, Iowa

NWS Quad Cities, IA issued this tornado warning at May 2, 2018, 7:51 PM CDT for Cedar County, Johnson County, Muscatine County, Iowa. It was in force for 20 min. 3 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 2, 2018, 7:51 PM CDT (00:51 UTC)
Expired
May 2, 2018, 8:11 PM CDT
In force
20 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
1.5 in

Counties Cedar County, IA, Johnson County, IA, Muscatine County, IA

The radar

The Quad Cities radar (KDVN), 72 km from the middle of the area, began a volume at 00:51 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 2, 7:59 PM CDTTSTM WND GST 60Hills, IA
May 2, 8:00 PM CDTHAIL 0.75Hills, IA
May 2, 8:14 PM CDTHAIL 0.882 Se Iowa City, IAPENNY TO NICKLE SIZE HAIL

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 2, 3:56 PM CDTSevere Thunderstorm WatchSPC9 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.9 hours before the alert went out and 78 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Davenport, at 00:00Z on 2018-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1023 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2018-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 69 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
1023 J/kg
Mixed-layer CIN
-37 J/kg
Mixed-layer LCL
1402 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
69 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.3
Supercell composite
5.1

Open this sounding in Storm Lab

The text

As transmitted.

899 
WFUS53 KDVN 030051
TORDVN
IAC031-103-139-030145-
/O.NEW.KDVN.TO.W.0005.180503T0051Z-180503T0145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
751 PM CDT WED MAY 2 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Southwestern Cedar County in east central Iowa...
  Southeastern Johnson County in east central Iowa...
  Northwestern Muscatine County in east central Iowa...

* Until 845 PM CDT
    
* At 750 PM CDT, a severe thunderstorm capable of producing a tornado
  was located near Hills, or 8 miles southwest of Iowa City, moving
  east at 25 mph.

  HAZARD...Tornado and ping pong ball size hail. 

  SOURCE...Radar indicated rotation. 

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely. 

* This dangerous storm will be near...
  University Heights around 800 PM CDT. 
  Hills around 805 PM CDT. 
  Iowa City around 810 PM CDT. 
  West Branch around 830 PM CDT. 
  West Liberty around 840 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Springdale, Cedar Valley, Iowa City Municipal Airport, Herbert Hoover
National Historic Site, Muscatine County Fairgrounds, Johnson County
Fairgrounds, University Of Iowa, Hills Access and Oasis.

This includes Interstate 80 in Iowa between mile markers 248 and 260.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4175 9125 4148 9121 4150 9152 4151 9153
      4151 9165 4163 9168
TIME...MOT...LOC 0050Z 256DEG 20KT 4156 9162 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

ERVIN
2 follow-up statements
478 
WWUS53 KDVN 030100
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
800 PM CDT WED MAY 2 2018

IAC031-103-139-030145-
/O.CON.KDVN.TO.W.0005.000000T0000Z-180503T0145Z/
Cedar IA-Johnson IA-Muscatine IA-
800 PM CDT WED MAY 2 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 845 PM CDT FOR
SOUTHWESTERN CEDAR...SOUTHEASTERN JOHNSON AND NORTHWESTERN MUSCATINE
COUNTIES...
    
At 759 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Hills, or 7 miles south of Iowa City, moving east at
25 mph.

HAZARD...Tornado and ping pong ball size hail. 

SOURCE...Radar indicated rotation. 

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely. 

This dangerous storm will be near...
  West Branch around 825 PM CDT. 
  West Liberty around 835 PM CDT. 

Other locations impacted by this tornadic thunderstorm include
Springdale, Iowa City Municipal Airport, Herbert Hoover National
Historic Site, Hills Access, Muscatine County Fairgrounds and Johnson
County Fairgrounds.

This includes Interstate 80 in Iowa between mile markers 251 and 260.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4171 9125 4148 9121 4150 9152 4151 9153
      4151 9165 4161 9166
TIME...MOT...LOC 0059Z 264DEG 22KT 4155 9152 

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

ERVIN
343 
WWUS53 KDVN 030111 RRA
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
811 PM CDT WED MAY 2 2018

IAC031-103-139-030119-
/O.CAN.KDVN.TO.W.0005.000000T0000Z-180503T0145Z/
Cedar IA-Johnson IA-Muscatine IA-
811 PM CDT WED MAY 2 2018

...THE TORNADO WARNING FOR SOUTHWESTERN CEDAR...SOUTHEASTERN JOHNSON
AND NORTHWESTERN MUSCATINE COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has 
weakened. Therefore, the warning has been cancelled.  However large 
hail, damaging winds and heavy rain are still possible with this 
thunderstorm.

A severe thunderstorm watch remains in effect until 1100 PM CDT for
southeastern and east central Iowa.

Remember, a Severe Thunderstorm Warning still remains in effect for
southern Johnson County.

LAT...LON 4171 9125 4148 9121 4150 9152 4151 9153
      4151 9165 4161 9166
TIME...MOT...LOC 0107Z 256DEG 20KT 4156 9145 

$$

ERVIN

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 7:18 PM CDTSevere Thunderstorm WarningDVNIowa, Johnson, Washington57 min
May 2, 7:24 PM CDTTornado WarningDVNJohnson, Washington51 min
May 2, 7:51 PM CDTSevere Thunderstorm WarningDVNScott39 min
May 2, 7:58 PM CDTSevere Thunderstorm WarningDVNKeokuk, Washington29 min
May 2, 8:07 PM CDTSevere Thunderstorm WarningDVNCedar, Johnson, Muscatine53 min
May 2, 8:19 PM CDTSevere Thunderstorm WarningDVNDelaware, Dubuque36 min
May 2, 8:34 PM CDTSevere Thunderstorm WarningDVNCedar, Clinton, Scott27 min
May 2, 9:51 PM CDTSpecial Weather StatementDVNScott24 min
May 2, 10:18 PM CDTSpecial Weather StatementDVNScott87 min
May 2, 11:40 PM CDTSpecial Weather StatementDVNLee, Van Buren50 min
May 3, 10:39 AM CDTRiver Flood WarningDVNClinton, Scott24 hr
May 3, 11:15 AM CDTRiver Flood WatchDVNJackson11 hr
May 3, 11:15 AM CDTRiver Flood WatchDVNLee7 days
May 3, 2:51 PM CDTSpecial Weather StatementDVNBuchanan39 min

Nearby

Tornado Warnings in Iowa, 2018Every tornado warning in 2018Tornadoes in 2018

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.